The present invention relates generally to improvements in a leveling pole, and more particularly to an improved type measuring instrument usable for measuring the height, length and width of objects or spatial dimensions in the fields of forestation, riparian operation, road building and construction work.
Most of the conventional leveling poles in general use comprise an outer liner member and a plurality of inner liner members inserted therein in telescopically slidable relation to each other so that when an operator wants to learn the exact height of a tree, for example, he may pull the inner liner members out of the outer liner member in regular increasing diameter sequence until the extremity of the innermost liner member reaches the treetop.
According to this, however, he cannot learn the height of the tree without reducing the full length of the outermost liner member from the length of the extended pole even after reading the latter length by graduations which are scaled up on the pole in reverse numeral order.
In order to eliminate the above-mentioned disadvantages of the conventional leveling poles, there has recently been developed a novel type of leveling pole wherein a tape-line is housed to enable an operator to digitally read the height of an object to be measured. However, in most cases the tape-line is made of such a steel strap material that when each liner member is pulled out or pushed into the outer liner member, the tape-line is also paied out or rolled in, always bringing about a rustling noise jarring on the ear caused by being rubbed against some inner wall portions of each member.
Further when an operator with the above-mentioned leveling pole works by a telegraph post or under a high-tension wire, he must always be exposed to the danger of an electric shock.